In Young's double-slit experiment the two slits are illuminated by the light of wavelength $5890 \stackrel{\circ }{\mathrm{A}}$ and the angular distance between the fringes obtained on the screen is $0.2°.$ If the whole apparatus is immersed in water then the angular fringe width will be, (the refractive index of water is $\raisebox{1ex}{$4$}\!\left/ \!\raisebox{-1ex}{$3$}\right.$)